Finnish investigators are examining whether a rudder problem experienced by a Flybe Nordic ATR 72-200 on approach to Helsinki bears any resemblance to that suffered by an Air Dolomiti aircraft that veered off the runway at Munich.
Pilots of the Flybe Nordic turboprop, arriving from Tampere on 19 August, found the rudder control pedals would not move and that they could not steer. French investigation authority BEA says a flight control fault indicator illuminated on approach.
After touchdown the aircraft (OH-ATH), with 31 on board, briefly left runway 22L but the crew regained control using nose-wheel steering. In a preliminary notification, the Finnish Accident Investigation Board cites a problem with the rudder travel limiter, which restricts rudder deflection above 185kt (213km/h).
German inquiries into the Air Dolomiti accident on 17 May found that the limiter had been in the position for high-speed flight as the aircraft attempted to return to Munich after an engine fire, and the pilots could not operate the rudder. The reasons for the difficulties have yet to be determined.
Finnish investigator Ismo Aaltonen says the board is contacting the German authorities as part of the Flybe Nordic probe. "It is difficult to say if there are similarities," he says. "[The Air Dolomiti crew] had many more problems."
Aaltonen says the Finnish inquiry has already listened to the cockpit-voice recorder and is looking at the pilots' actions, the operating manual and training aspects. He adds that landing in the high-speed configuration is permissible under certain restrictions.
Investigators are examining the manufacturer's operating instructions for rudder-movement failure. Aaltonen says other apparently similar events will also be analysed. Despite the temporary runway excursion, he says, the aircraft was not damaged.